Synchronizing system.



A. F. DIXON. sYNcHnoNlzmc svskgm. APPLICATlON FILED HOY. 2| IBN.

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f Patented 0Gt.1,191s., v

UNITED STATES PATENT OFFICE.

MOS F. DIXON, 0F NEWARK, 'NEW JERSEY. ASSIGNOR. BY MESNE ASSIGNMENTS. T0 WESTERN ELECTRIC COMPANY. INCORPORATED. A CORPORATION F NEW YORK* SYNCHRONIZING SYSTEM.

Application led November 2` 1914.

Be itknown that l. Anus Fnnnicnii'it DIXON, a citizen of the liiiited States. residing 'at Ne artt` in the county of Essex alid State of New Jersey, havey invented Certain new and useful Improvements in Synchronizing Systems, ot' which the tolloii'ingis a t'ull, clear, concise, and exact description.

This invention"relates to synchronizing systems for multiplex telegraphy. and its principal object is to provide. an improved method of operation and s rstoin whereby synchronism normally obtained by signal c-urrent. reversals can be automatically inain tained duringV non-signaling intervals.

The invention as heroin shown and as it is particularly designed to be utilized, is embodied iii a printing telegraph system ot' the multiplex high spoed typo, for which distribute-rs ot' the Baudet type are used, one of such t'listributers being located at the sending station and the other at the receiving `station. As there is only a Single line wire between the sending and receiving stations, it is necessary to synchronize the.

distributorsl either by sending extra synelironizingl impulses over such line wire or by utilizing' parts ol a signal impulse for s yiiehronizintr. ln synchronizing with extra s i'nchroni/,ing impulses it is found that time is wasted in sending the. extra synchronizing impulsos. and in Isynchronivfunr with signal impulses dillieult-y is encountered in maintaining synehronisni at times wheli sig4 iials are not being sont. Iiiaeeordance with a l'eatureot the present invention two or more distributers are maintained in synehrouisni duringr the sending of a message by means ot" changes in polarity in the'signalinlgr impulses. and moans are provided 'wherebya in case no signaling impulses are being sont or in ease several similar signals are. sont, without change in polarity. the, polarity of' tho current in the line is nevertheless periodically changed so that synchroniziner impulsos are, produced andthe distributors are maintained in syliohronjtsn'i'.

ln accordance with this fature of the in`- aeeoniplish this result all otthe transmitters Specification of Letters Patent. i

'PatentedfOctu 1, 1918.

Serial No. 869,784. n

y contacts ot' the corresponding quadrant at the receiving station are so arranged that the line relay closes the local circuit to the selecting magnets ot' the, printer t'or each positive impulse: similarly in the next quad rant the transmitters are ar 'angeli so that their contactsl normally connect, with positive'battei'y. and the distributor at the receiving station is so arranged that the contacts of the corresponding quadrant are made operatire when a negative impulse is impressed on the lino. By i'irtue. ot. this arrangement. whether or not signals are being sont each time that the distributor brushes more, troni one quadrant to the next, the. polarityof the line current will change and will more the armature ot' the line relay from the positive. to the negative, eon tact. or the reverse, as the ease may be, and

4will by so doingr cause the production of a.

-welhknown types of motors nia be used' for driving the distributors, and their s ds may be, either mechanically or electrically altered to briner them -into synchronism.

ln the partieular system which'the a plicaiit prefers to utilize and whicli's disc 0806.' herein, the :sil'nchront/.iner impulses,` under certain conditions. eausethe operatln 0f electrta-responsive doiieosVw'hich are udn t` ed to either electrically or mechanica ly modify the Speed of' the distributor:

'l` ne` above and other 'objects oi this invention will be fully set forth in the vfollowing description and ctanis, and will be more readily understood by reference to the aeeomimnying drawing in which the system is diagranunatieally Shown.

ln the. drawing!1 1 and 2 denote generally the distributors at the. sending and receiving stations. These distributors are of thi.

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usual Baudet type and may be provided with as many sections and sets of contacts as the traiic conditions niay demarul. On the drawings, hov'vever7 they are shown as being provided with tour sections or quadrants and four sets of contacts. The sending distributor l. is provided with four quadrants 3 which` are electrically connected together and to the line, Corresponding to each. quadrant 3 'is a set of five contacts illustrated at 4 and 5. The brush carrying,r arin 6, 'which is rotated by power driven shaft 7 in the direction of the arrow, carries two brushes which are electrically 'connected and which contact respectively with the quadrants and contacts, being adapted to successively connect the contacts to the quadrants and to the line.

For the salie of convenienoc1 the quadrant to which the contacts #l are in l ivid1ixal will. be referred to as the first quadrant, and the quadrants to which the com-acts are indi.- vidual will be reti-'i lo as the fourth quadrant, and the f ,-pf .ing qui on the receiving distribut r will be lili wise referred to as the first and f-fuirth quadrant The contacts 4: are each connected with the movable contactsl 8 of the transmitter, which movable cont-acts in their normal position, as indicated, are connected. to negative battery and are adapted to be displaced in any combination to forni a signal., and when di placed move to the positive side and connect positive battery to the contacts 4i. The contacts 5 similarly are connected to thc movabl'e contacts of the fourth transmitter, which contacts, ae A"ion-in, normally .in connection with posit-ive ha. f and may be moved to place negative battexy on the con tacts'. imilarly the contacts ci the second and third qnafl its may be connected to the nioifablc coi' a.' of two other transmitters, the movable contacts et' the trans-- mitter of the second quadrant being normally in connectionwith positive battery, and ofthe transmitter of thethird quadrant normally in connection with negative battery. As before stated any number ot' sections may be employed, it only being essential that the transmitters associated with adjacent sections should be arranged so that the movable contacts thereof are normally in connection with battery of opposite polarities.

It can be seen that due to this arrangement when the movable arm 6 passes from the fourth to the tirst quadrant or from the first to the second or second to third or third to fourth, if no selective signals are being sent, the transmitter contacts beingr in normal position, the polarity of impulses inipressed on the line 10 will change each time the distributer 4arm moves from the one quadrant to the adjacent quadrant.l

The impulses of current impressed on the line 10 pass through tbe line relay 11 and move the movable tongue 12 thereof either to the Contact 13 or contact 14, depending upon whether the impulse is positive or negative, the relay being so arranged that the tongue 1 2 will stay in the position to which it is moved until the polarity of the current is changed. Connected with the armature 12 is a source of local battery 15 which is connected to either the Contact 13 or 1-1, depending upon 'the operation of the relay 11. The contact 18 is connected as indicated to the quadrants 18 and 19, and the contact 1+i to the quadrants 16 and 17 of the distributor at the receiving sta-tion, or, in'other words, the contact 1.3 is connected to the Iirst aud.thi1d quadrants of the distributor, and the contact 14 to the second and fourth quadrants. Individual to each quadrant in this distributer is a set of contacts which correspond to thc contacts -l and 5 of thc sending distributor. These contacts in the fourth and first quadrants being represented by the reference numerals and respectively, The receiving distributor is provided with distributing arm 22, which. is adapted to be rotated by shaft in the direction of the arrow in synchronisin with' the distributor arm G of the sending distrib'uter. The receiving distributer 2 is provided Withfan additional set of contacts for each quadrant which are. the saine in number as the contacts 21, and as shown are smaller than such contacts 21. These contacts which are the synchronizinr contacts are designated in the tiist an( fourth quadrants by the reference numeral-z S23 and 24. A continuous ring contact is also provide;1t an(I the distributing arm is provided v` .ith fo pairs of brushes, the brushes of each pair beineT electrically connected, the arrangement being such that as the f lislributci"erin nieves over the contacts, the contacts 20' and 21 will be successively connected electrically to the quadrants 17 and 18, and the synchronizing contacts -21 and 23 will be successively electrically connected to the ring contacts rants 16 and 19, as indica-ted, are also provided with sets of synchronizing-contacts, as well as the contacts corresponding tocontac-ts 20 and 21, the connections for-convenience being shown only in the fourth and .first quadrants. 21 is a set of selecting magnets 26, -there bein g one selecting magnet connected to .each Contact, and the contacts 20 are similarly connected to a similar. setnof selecting magnets 27. The magnets and 27 are asso-` ciated with two different printing instruments and operate in the well-known manner, when energized in combinations ,determined by lthe combination of impulses.A Sent by the corresponding transmitters .at-fthe.-

sending station, to select the character which The quad- Connected to the contacts it is Adesired to record and to canse the re cording of such character. As printing instruments of this type are well known in the art it ,has only been deemcd'necessary to illustrate the selecting magnets thereof.

Synchronizing contacts 23, 21, ctc., are connected in multiple and are connected to one windii'lg of the relay 28. The other winding of the relay 28 acts as a locking Winding when such relay is energized, and forms part ot' the circuit controlling the magnet 29. The magnet 29 may be employed for electrically correcting the speed of the driving mechanism of the receiving distrib uterin a manner similar to that disclosed in Patent No. 1,185,712, dated June 6, 1916, or it may be employed for mechanical correction, z'. e., the magnet 29 may be used for shifting the brush arms of the receiving distributer in a manner similar to that disclosed in applicants copending application Serial No. 831,167, filed April 11, 1914. The ring 25 is connected to the secondary winding 3U of an induction coil, the primary winding 31 of which. connected to the contact 14.

It is the general practice in synchronizing distributors to normally run one of the distributers, which is termed the correcting distributcr, at as constant a speed as is practicable, and, by means of slight corrections, to automatically adjust the speed of the other or corrected distributer to keep the two in the. proper phase relation. Thus, the cor rected distributor may be adjusted to normally run faster or slower than the correcting distributer, speedV correcti ons heilig made by respectively slowing down or speeding up the corrected distributer, or adjustments may he made to a mean speed, corrections being made by either raising or. reducing the speed ofthe corrected distributor as it gains on or falls behind the other distributor. Assuming in this case that the distributer 1 at the sending station is a correcting distributor and is adjusted to run at a. constant. speed, and that the receiving distributor 2- is the corrected distributer and is adjusted to normally run at a slightly higher speed than the correcting distributor` it the two distributers are running. in exact synchronism and aresending a given character while the distributer arms are passing, for instance, over the first quadrants, impulses will be sent. out over the line in accordance with the set condition of the transmitter associated with the first quadrant; As the distributor Y arm (3 contacts with the tirs-t contact 4 ot' the set, it' the first transmitter contact 8 has been moved over to the positive side a posit-ive impulse will be sent out on the line, and. if the contact: has not been moved, a negative impulse will be. sentout on the line. Conscquently the armature 12 ot' the line relay 11 will be moved against the posit-ive or negative contacts 13 or 1l, as the case may be.

If moved against the posit-ive contact a Circuit will be closed from battery 15 with the armature 12 and contact 13. quadrant 18, distributer arm contact 21 and selecting magnet 2G, and for a given signal set up on 70 the transmitter the magnets 26 will be energized or not, in accordance. with the combi nation of impulses sent from the transmitter. The operation ot' the transmitter, the contacts of which arc shown at 9. and the select- 'I5 ing magnets 27, both being of the fourth quadrant, are identically the same, with the, exception that the fourth quadrant selecting magnets will be energized only when negative impulses are sent, a negative. impulse of l!) the fourth quadrant being equivalent to a poslt-lve impulse of the first quadrant asfar as the effect on the selecting magnets is concerned.

Thus, assuming that a given character is l5, represented in the alphabet by two positives, a negative and` two positives in the first quadrant, the same character will be represented in the fourth quadrant by two negatives, a positive and two negatives. This will not, however, necessitate any change in the transmitter mechanism associated with alternate quadrants. exceptas regards the normal position ot the nu 'able contacts thereof. nl

It will be noted that in sending the characters described above, the polarity of the current changes twice, irrespective of the quadrant from which such signal is heilig sent, and as the majority ot' the characters 100 of the Baudet alphabet require a change ot polarity under normal conditions, such changes of polarity will be very frequent in transmitting the ordinary message. It will be observed that for every change otl polarity the armature 12 ot' the. line relay will be moved either from the contact 13 to the contact 11, or reversely. lf the two distributors are running in exact synchronism, this movi ment of the armature 12 will have no other 110 effect than that of energizing certainwot' the selecting magnets, asthe ch'ange in polarity will occur-just befor thc outer set of brushes make. contact with the s vncln'oniaing contacts 23, or just as the brushesleave .one con 115 tact 21 and more toward the next @Tnt ict 2l. 1f, however. the distrhutcr 2 isV moving faster than distributor l, as assumed. before this change of polarity occurs, the brushes on the distributor arin will make contact with the synchronizingcontact. and will elcci trically connect. one. ol said synchronizing contacts with thc ring contact 25. As a synchronizing cont-act 23 orzZ-i. as the cascmay be. is then conucctlal to thc ring .fhe change of polarity in the current and the consequent moving of the armature l2 will cause an induced pulsation of the current to pass through the relay 28. [For i||stancP,-.lf the armature 12 moves from contact 13 to 1:30

60 therefrom, as the oase ma contact 14, a circuit will be closed through the primary coi-l 31 of the induction coil. This will induce an imp ulse of the secondary coil 30, which will pass by .way of the ring and synchronizing contact 23, all of which are connected in multiple to the left-hand winding of the relay 28. The relay 28 will thereupon be energized and close at its con tact a locking circuit for itself from battery 10 32, back contact of magnet 29, Winding of magnet 29, front contact of relay 28 to ground. The energization oi the magnet 29 will break the locking circuit of relay 28. In the embodiment herein illustrated the 16 magnet 29 is arranged to effect a mechanical correction of the corrected distributor. In

this case each energization of the magnet 29 will cause it to `attract its armatures and, by means of pawl 34, a suitable ratchetmechanisni will be rotated to move the brushes of the corrected distributer back or forward one step as the case may be. .lust so long as the corrected distributer is running faster than the correcting distributor, a, synchroniz- 26 ing impulse will be brought into action for each reversal of polarity in the line current to step back the brushes of the corrected distributer until it is again in synchronisni 'with the correcting distributer.

If, at the time when no selective signals are being sent, the distributers are not runningr in synclironism, the system will operate as ollows to maintain suoli distributers in synchronism; It will be observed that -when 3b the arm 6 of the distributer 1 is passing over the fourth quadrant and'no signals are being.

sent, positive impulses will be impressed on the-line 10, and armature 12 of the line relay 11 will bemaintained in contact with contact 13` However, as soon as ,the distributer arm passes from the fourth to the first quadrant, the armature 12 will move over to con tact 14, as negative impulses will be imressed on the line in the first quadrant. is change ofl polarity, provided the distributors are not in exact synchronism, will be utilized exactly as in the case of4 a changev of polarity when a signal is |being sent to bring the distributers into' synclironism. Similarly'when thedistributtr arm passes from' the first to the secondquadrant a change: of polaritywill occur,and from the second tothe third quadrant another change of polarity will occur, making in allin the system` disclosed four changes of polarity for i each complete rotation of the c listributer. These changes inA polarity will either cause battery to be impressed uponthe primary 'cbil'll of the. induction coil, or removed be.' .In either case an' impulse will be in uced in the sccondary, .which impulse will pass by'ivay lof the rin contact 25 to thesynchronizing conT tacts 2g, 24, to the relay 28, causing the clpownit e 6l eration of the magnet 29 to slow opposite polarity are received.

'arranged to send to line current of a p0u corrected distributer. Thus it will be seen. that the synchronizing impulses will be roduced and the distributers maintains in synchronism, irrespective of Whether or not signals are being sent on any, or all of the quadrants. It will also be apparent rom an inspection of the drawing that if the movable contacts of any transmitter are in normal position, z'. e. if no 'Signals are being sent, none of the selecting magnets of the receiver 76 controlled by such transmitter will be energized, as the line relaywill be shifted to break the circuit at its contacts. Thus in the case of the .first quadrant the movable contacts 8 will be normally connected to negative battery and the armature12 will be moved against contact 14, This will place the potential of battery 15 on the contacts of the second and fourth quadrants, which will be Without effect as'the arm 22 is at this time moving in the first uadra-nt.

An advantage of t e system of the invention resides in the fact that synchronism is maintained 'while no signals are bein sent, without the use of any extra or comp icated apparatus, it only being necessary to alter the normal polarities of the contacts of the transmitters associated with alternate quad-- rants.

The invention claimed is: 05

1. In a' multiplex telegraph system, in combination with a, transmission line, a plurality of transmitting stations, means for successively connecting said stations to, said line, each of said stations when at rest beingarranged to send to line currentof a polarity different from thatl sent to lin'e by the preceding and succeeding transmitting Stations wliereby the line current is periodically reversed, a receiving d'istributer liavinga plurality of receiving sections corresponding in number to the number of said transmitting stations, a local source of current, and means responsive to said reversals of line current for connect-ingsaid local source "of current to alternate ones of said receiving sections when line impulsesof one polarity are received and to intervening ones ofsiaid receiving sections when line impulses ofthe 2. In -amultiplex telegraph system in combination Within transmission line, a plu rality of transmitting stations, means for successively connecting said stations to said line, each of said stations when at rest being l izo larity. diii'erent from that sent to line bythe preceding and succeeding transmitti'n stations whereby the line current is perio ically'- reversed, a receiving distributer havin a'125`v lurality-of receiving sections correspon ing in number to the' number of said transmitting stations, a local source of current, means responsive .to said reversals of line current for connecting said local source of current 180 :,esomaa 'to alternete ones of said receiving sections when line iinpulse'ofone polarity are re ceived und to intervening ones of said 1re ceving" sections when linefimpulses of the opposlte polarity are received;fandl other means responsive to sind reversalsfof'rllne currentfor maintaining said receiving dirtributer in synchroni-sxn `ivithsuid, *transmity ting distributer.

3.Ina multiplex telegraph system in combination with a transxmsl'sion line, a plurelity of transmitting stations, e sending rotur distributer for successivelyconnecting I ber" to the number of said transmltting stal sai stations to said 1ine,eech of said-stetions when' at rest being arran ed to send to line current of a, polarity di erent from that sentto line'by the preceding and succeedingA transmitting stations whereby` the line current is periodicelly reversed, a recelving rotary distributer havirg a, plurality of receiving sectionsccorrespon in numlng 4circuit connections for sending a former upon each reversal of the line cur rent, andy means connected with the seconder of said vtransformer and responsive to sai In witness whereof, I hereuntoY subscribe "my name this 30 day of 4Cctober A. D., 1914'.

. 5 AMOS F. DIXON. Witnesses.:

E. Enmmf,

, K.,L. STAHL;

pulse for maintaining lseid receiving. distributer in synchronism with .said transmitting' distributer. 

